CN103123792B - Optical information recording/reproducing device and method - Google Patents

Abstract

The present invention provides optical information recording/reproducing device and method, optical information recording medium, in the optical information recording/reproducing device utilizing holography, the zero point of reference light angle between device and the error of unit quantity can be modified, carry out compatible high record between device and reproduce.Its technical scheme is, detection is suitable for the reference light angle of the angle modification data reproducing record in optical information recording medium, is modified zero point and the unit quantity of reference light angle when recording or reproduce based on this detection angles information.

Description

Optical information recording and reproducing apparatus and method

technical field

The present invention relates to a device, method and medium for recording and reproducing information on an optical information recording medium using holography.

Background technique

At present, due to the standardization of Blu-ray Disc(TM) using blue-violet semiconductor lasers, commercialization of optical discs having a recording density of about 100 GB has also become possible for consumer use. And in the future, optical discs will also need to have a larger capacity than 500GB. However, in order to realize such an ultra-high density in an optical disc, a new type of high-density technology is required, which is different from the conventional high-density technology based on a shorter wavelength and a higher NA of an objective lens.

In conducting research on next-generation memory technology, a holographic recording technology for recording digital information using holography has drawn attention. As a hologram recording technique, there is, for example, Japanese Patent Laid-Open No. 2004-272268 (Patent Document 1). This publication describes a so-called angle multiplexing recording method in which different page data are displayed on a spatial light modulator for multiplex recording while changing the incident angle of reference light on an optical information recording medium. Furthermore, this gazette also describes a technique of shortening the interval between adjacent holograms by converging signal light with a lens and disposing an aperture (spatial filter) at the beam waist.

Moreover, as a hologram recording technique, there exists WO2004-102542 publication (patent document 2), for example. This publication describes an example of using the shift multiplex method, in which the light from the inner pixel in one spatial light modulator is used as the signal light, and the light from the outer ring-shaped pixel is used as the reference light, and the same lens is used. A hologram is recorded by converging two light beams on an optical information recording medium and interfering signal light and reference light near the focal plane of a lens.

As a technique for adjusting a reproduction laser when reproducing a hologram, there is, for example, Japanese Patent Laid-Open No. 2007-256949 (Patent Document 3). In this gazette, it is described that "in a holographic storage medium, a reference tilt hologram for specifying a reference incident angle in a radial tilt (radial tilt) direction is recorded in advance. The recording position of the oblique hologram is irradiated with reference light, and the reference incident angle (reference angle Sr) of the reference light in the radial direction is detected according to its light-receiving state. Then, for displacing the holographic storage medium in the radial direction The tilt actuator 19 is driven and controlled so that the incident angle in the radial tilt direction of the reference light matches the reference angle Sr. After that, the hologram storage medium is irradiated with signal light and reference light to perform recording/reproducing operations."

Patent Document 1: Japanese Patent Laid-Open No. 2004-272268

Patent Document 2: Publication No. WO2004-102542

Patent Document 3: Japanese Patent Laid-Open No. 2007-256949

Contents of the invention

However, in the optical information recording and reproducing device using holography, it is very important to control the angle of the reference light when recording and reproducing information, but there are errors in the zero point and unit amount of the reference light angle between different devices, and it is difficult to carry out inter-device Problems with recording reproduction with high compatibility.

The technology described in Patent Document 3 adjusts the reference beam angle by referring to the reference hologram in advance, and can cope with the disc tilt or the difference in the zero point of the reference beam angle between devices, but cannot cope with the unit amount of the reference beam angle between devices. error.

In view of the above problems, an object of the present invention is to provide an optical information recording and reproducing device, a method thereof, and an optical information recording medium capable of recording and reproducing with high compatibility.

In order to solve the above-mentioned problems, the present invention employs, for example, the following means.

The present invention provides an optical information recording and reproducing device, which uses holography to record and/or reproduce information on an optical information recording medium. the first angle information of the reference light angle reproduced in the angle correction data; and the angle correction unit based on the first angle information detected by the angle detection unit and when the angle correction data is recorded The second angle information of the reference light angle is used to correct the reference light angle during recording or reproduction.

Furthermore, the present invention provides an optical information recording medium for recording information using holography, characterized in that the optical information recording medium includes an angle correction data area used for correcting the angle of reference light.

In addition, the present invention provides a method for recording and reproducing optical information, using holography to record and/or reproduce information on an optical information recording medium, which is characterized in that it includes: an angle detection step, detecting an angle suitable for recording on the optical information first angle information of a reference light angle for reproducing the angle correction data in the recording medium; and an angle correction step based on the angle information detected by the angle detection step and the reference when the angle correction data is recorded. The second angle information of the light angle corrects the reference light angle at the time of recording or reproduction.

According to the present invention, it is possible to perform recording and reproduction with high compatibility between devices.

Description of drawings

FIG. 1 is a schematic diagram showing the outline of the present invention.

Fig. 2 is a configuration diagram showing an example of an optical information recording and reproducing device.

Fig. 3 is a diagram showing an example of a pickup in the optical information recording and reproducing device.

Fig. 4 is a diagram showing an example of a pickup in the optical information recording and reproducing device.

Fig. 5 is a diagram showing an example of an operation flow of the optical information recording and reproducing device.

Fig. 6 is a diagram showing an example of an optical information recording medium.

FIG. 7 is a diagram showing an example of the relationship between the reproduction light intensity and the reference light angle when the angle correction data is reproduced.

Fig. 8 is a flowchart showing an embodiment when a medium is loaded in the optical information recording and reproducing apparatus.

9 is a flowchart showing an example of the operation of reference beam angle correction in the optical information recording and reproducing apparatus.

Fig. 10 is a diagram showing an example of a pickup in the optical information recording and reproducing device.

11 is a schematic diagram showing an example of a relationship between a diffracted light angle and a detection position when searching for a reference light angle corresponding to angle correction data.

Explanation of reference signs

1...optical information recording medium, 2...area for angle correction,

10...optical information recording and reproducing device, 11...pickup,

12...Phase conjugate optical system, 13...Disc curing optical system,

14...Optical system for detection of disc rotation angle, 15...Optical system for disc curing,

16... Optical disc curing optical system, 17... Optical information recording and reproducing device,

50... rotating motors,

81...Access control circuit, 82...Light source driving circuit,

83...servo signal generation circuit, 84...servo control circuit,

85...signal processing circuit, 86...signal generating circuit,

87...Shutter control circuit, 88...Disc rotation motor control circuit,

89...controller, 90...angle detection circuit, 91...angle correction circuit,

92...Input and output control circuit, 93...External control device,

201...light source, 202...collimating lens, 203...shutter,

204...1/2 wave plate, 205...polarizing beam splitter,

206...signal light, 207...reference light,

208...beam expander, 209...phase mask,

210...relay lens, 211...polarizing beam splitter,

212...spatial light modulator, 213...relay lens,

214...spatial filter, 215...objective lens,

216...polarization direction conversion element, 217...reflector,

218...reflector, 219...reflector, 220...actuator,

221...lens, 222...lens, 223...actuator,

224...reflector, 225...photodetector,

230...actuator, 231...reflector, 232...lens,

233... photodetector

detailed description

Examples of the present invention are described below.

[Example 1]

The first embodiment in the present invention will be described using FIGS. 1 to 9 .

FIG. 2 is a block diagram showing a recording and reproducing apparatus for an optical information recording medium that records and/or reproduces digital information using holography.

The optical information recording and reproducing device 10 is connected to an external control device 93 through an input/output control circuit 92 . When performing recording, the optical information recording and reproducing device 10 receives an information signal to be recorded from an external control device 93 via an input/output control circuit 92 . When performing reproduction, the optical information recording and reproducing device 10 sends the reproduced information signal to the external control device 93 through the input/output control circuit 92 .

The optical information recording and reproducing device 10 is equipped with a pickup 11, a reference light optical system 12 for reproduction, a curing (cure) optical system 13, an optical system 14 for detecting an optical disc rotation angle, and a rotating motor 50. 50 while rotating the structure.

The role of the pickup 11 is to emit reference light and signal light to the optical information recording medium 1, and to record digital information on the recording medium by holography. At this time, the information signal to be recorded is sent to the spatial light modulator in the pickup 11 by the controller 89 through the signal generating circuit 86, and the signal light is modulated by the spatial light modulator.

In the case of reproducing the information recorded in the optical information recording medium 1, the reference light emitted from the pickup 11 is generated by the reproduction reference light optical system 12 so that it enters the optical information recording medium in the direction opposite to that used for recording. light waves. The reproduction light reproduced by the reproduction reference light is detected by a photodetector described later in the pickup 11 , and the signal is reproduced by the signal processing circuit 85 .

The irradiation time of the reference light and the signal light irradiated on the optical information recording medium 1 can be adjusted by controlling the opening and closing time of the shutter in the pickup 11 by the controller 89 via the shutter control circuit 87 .

The curing optical system 13 functions to generate light beams used in pre-curing and post-curing of the optical information recording medium 1 . The pre-curing is a pre-process of irradiating the desired position with a predetermined light beam before irradiating the reference light and the signal light when recording information at a desired position in the optical information recording medium 1 . The post-curing is a post-process of irradiating a predetermined light beam after information has been recorded at a desired position in the optical information recording medium 1 so that additional recording cannot be performed at the desired position.

The optical system 14 for detecting the optical disc rotation angle is used to detect the rotation angle of the optical information recording medium 1 . When the optical information recording medium 1 is adjusted to a predetermined rotation angle, the optical system 14 for detecting the rotation angle of the optical disk can be used to detect a signal corresponding to the rotation angle, and the detected signal can be passed through the controller 89 through the disk rotation motor control circuit. 88 controls the rotation angle of the optical information recording medium 1 .

A predetermined light source driving current is supplied from the light source control circuit 82 to the light sources in the pickup 11 , the curing optical system 13 , and the optical disc rotation angle detection optical system 14 , and light beams can be emitted from each light source with a predetermined light quantity.

In addition, the pickup 11 and the optical disc curing optical system 13 are provided with a mechanism capable of sliding their positions in the radial direction of the optical information recording medium 1, and the positions are controlled by the access control circuit 81.

The angle detection circuit 90 acquires from the pickup 11 a signal obtained by reproducing the angle correction data recorded in the angle correction area in the optical information recording medium 1 and the corresponding reference light angle before recording or reproducing information, A reference beam angle suitable for reproducing the angle correction data is detected and output to the angle correction circuit 91 . A detailed example of the detection method of the reference light angle will be described later.

The angle correction circuit 91 acquires a reference light angle suitable for reproducing the angle correction data from the angle detection circuit 90, calculates the zero point of the reference light angle and the correction value of the unit amount based on the reference light angle and the theoretically predicted reference light angle, and outputs to controller 89. A detailed example of the calculation method of the zero point of the reference light angle and the correction value of the unit amount will be described later.

However, the recording technique using the angle multiplexing principle of holography tends to have a very small tolerance for the deviation of the angle of the reference light.

Therefore, it is necessary to provide a mechanism for detecting the amount of deviation of the reference beam angle in the optical pickup 11, and to generate a signal for servo control by the servo signal generation circuit 83 in the optical information recording and reproducing device 10, and to correct the deviation by the servo control circuit 84. Amount of servo mechanism.

In addition, among the pickup 11 , the curing optical system 13 , and the optical system 14 for detecting the rotation angle of the optical disk, some or all of the optical system structures can also be organized and simplified into one.

FIG. 3 shows the recording principle of an example of the basic optical system configuration of the pickup 11 in the optical information recording and reproducing apparatus 10 . The light beam emitted from the light source 201 passes through the collimator lens 202 and enters the shutter 203 . When the shutter 203 is opened, after the light beam passes through the shutter 203, the polarization direction is controlled by an optical element 204 composed of a half-wave plate, etc., so that the light quantity ratio of p polarization and s polarization becomes a desired ratio, and then enters the PBS (Polarization Beam Splitter, polarizing beam splitter) prism 205.

The light beam passing through the PBS prism 205 acts as the signal light 206 , and after the diameter of the beam is expanded by the beam expander 208 , it passes through the phase mask 209 , the relay lens 210 , and the PBS prism 211 and enters the spatial light modulator 212 .

The signal light to which information has been added by the spatial light modulator 212 is reflected by the PBS prism 211 and propagates through the relay lens 213 and the spatial filter 214 . After that, the signal light is condensed on the optical information recording medium 1 by the objective lens 215 .

On the other hand, the light beam reflected on the PBS prism 205 serves as the reference light 207, and after being set to a prescribed polarization direction by the polarization direction conversion element 216 according to recording or reproduction, passes through the reflection mirror 217 and reflection. Mirror 218 is incident on galvanometer mirror 219 . Since the angle of the galvanometer mirror 219 can be adjusted by the actuator 220, the incident angle of the reference light incident on the optical information recording medium 1 after passing through the lens 221 and the lens 222 can be set to a desired angle. In addition, in order to set the incident angle of the reference light, an element that converts the wavefront of the reference light may be used instead of the galvanometer mirror.

In this way, signal light and reference light are incident on the optical information recording medium 1 and overlapped with each other to form an interference fringe pattern in the optical information recording medium, and information is recorded by writing the pattern into the optical information recording medium. In addition, since the incident angle of the reference beam incident on the optical information recording medium 1 can be changed by the galvanometer mirror 219, it is possible to perform recording using an angle multiplexing method.

Hereinafter, for holograms recorded in the same area with different reference light angles, the hologram corresponding to each reference light angle is called a page, and the set of angle-multiplexed pages in this area is called a book. ).

FIG. 4 shows the reproducing principle of an example of the basic optical system configuration of the pickup 11 in the optical information recording and reproducing device 10 . In the case of reproducing the recorded information, the reference beam is made incident on the optical information recording medium 1 as described above, and the light beam transmitted through the optical information recording medium 1 is utilized with a galvanometer mirror whose angle can be adjusted by the actuator 223. 224 to reflect it, thereby generating its phase conjugate light.

The signal light reproduced by the phase conjugate light propagates through the objective lens 215 , the relay lens 213 , and the spatial filter 214 . Thereafter, the signal light passes through the PBS prism 211 and enters the photodetector 225, whereby the recorded signal can be reproduced.

FIG. 5 shows the flow of recording and reproducing operations in the optical information recording and reproducing device 10 . Here, in particular, the flow of recording and reproduction using holography will be described.

Fig. 5 (a) shows the operation flow until the preparation for recording or reproduction is completed after the optical information recording medium 1 is inserted in the optical information recording and reproducing device 10, and Fig. As for the operation flow of recording information, FIG. 5( c ) shows the operation flow from the ready state to the reproduction of the information recorded in the optical information recording medium 1 .

As shown in FIG. 5( a ), when a medium is inserted ( 401 ), the optical information recording and reproducing apparatus 10 performs, for example, disc discrimination ( 402 ) to determine whether the inserted medium is a medium for recording or reproducing digital information using holography.

If the result of disc discrimination is determined to be an optical information recording medium that uses holography to record or reproduce digital information, the optical information recording and reproducing device 10 reads the control data set in the optical information recording medium (403), and acquires, for example, Information on the information recording medium, and information on various setting conditions at the time of recording and reproduction, for example.

After reading the control data, various adjustments corresponding to the control data and learning processing related to the pickup 11 are performed ( 404 ), and the optical information recording and reproducing apparatus 10 completes preparations for recording or reproduction ( 405 ).

The operation flow from the ready state to recording information is shown in FIG. 5( b ). First, the data to be recorded is received ( 411 ), and information corresponding to the data is sent to the spatial light modulator in the pickup 11 .

Thereafter, various learning processes for recording such as power optimization of the light source 301 and exposure time optimization of the shutter 303 are performed as necessary ( 412 ) so that high-quality information can be recorded on the optical information recording medium.

Thereafter, in the tracking operation (413), the access control circuit 81 is controlled to position the pickup 11 and the curing optical system 13 at predetermined positions on the optical information recording medium. When the optical information recording medium 1 has address information, the address information is reproduced to confirm whether it is located at the target position. If it is not located at the target position, the amount of deviation from the predetermined position is calculated, and the positioning operation is repeated again.

Thereafter, a predetermined area is pre-cured using the light beam emitted from the curing optical system 13 (414), and then data is recorded using the reference light and signal light emitted from the pickup 11 (415).

After the data is recorded, post-cure ( 416 ) is performed using the light beam emitted from the curing optical system 13 , and the data can also be verified as required.

The operation flow from the ready state to the reproduction of the recorded information is shown in Figure 5(c). First, in the tracking operation (421), the access control circuit 81 is controlled, and the pickup 11 and the reproduction reference light optical system 12 are The position is positioned to the specified position of the optical information recording medium. When the optical information recording medium 1 has address information, the address information is reproduced to confirm whether it is located at the target position. If it is not located at the target position, the amount of deviation from the predetermined position is calculated, and the positioning operation is repeated again.

Thereafter, reference light is emitted from the pickup 11, information recorded on the optical information recording medium is read (422), and reproduced data is transmitted (423).

Fig. 6 shows an example of an optical information recording medium. The optical information recording medium 1 has an angle correction region 2 in addition to the information recording region. Angle correction data of a predetermined pattern (pattern) is recorded in the angle correction area 2 at a predetermined reference light angle. Information about the data for angle correction, such as the pattern of the data for angle correction and the angle of the recording reference light, may be stored in the optical information recording medium itself, or may be stored in the device or a device that controls the device, or in a box for accommodating the optical information recording medium. .

In addition, the angle correction data may be pre-recorded when the medium is shipped, or may be recorded by the first device that records on the optical information recording medium. In addition, the page data included in the angle correction data may have the same pattern as the data portion, or the data may be arranged only in a portion where Bragg selectively expresses strongly. Among them, as a method of forming a page in a portion where Bragg selectivity is strong, for example, a method of forming a page pattern such that the angle formed by the reference light and the signal light is as large as possible in the optical information recording medium can be considered. By constituting a page only at a portion where the Bragg selectivity is strong, the full width at half maximum of the reproduced light intensity with respect to the angle of the reference light (that is, the half maximum width of the curve of the reproduced light intensity with respect to the reference light intensity) is narrowed, so it is possible to accurately Detect the reference light angle. In Fig. 6, the area 2 for angle correction is drawn in the central part of the optical information recording medium 1, but the area 2 for angle correction is not limited to this position, it can be in any position such as the inner periphery or the outer periphery, and a plurality of them can also be prepared. . The advantage of being arranged in the center of the optical information recording medium, for example, lies in the fact that, since the effects of expansion and contraction and crosstalk from adjacent recording portions are isotropic, it is possible to suppress reference light caused by the influence of external disturbances. Angle detection error. The advantages of arranging the inner peripheral part or the outer peripheral part can be listed, for example, because the angle correction data can be arranged in the management area, etc., so it is easy to distinguish between the user data and the angle correction data, and the processing during playback will not become cumbersome.

FIG. 7 shows an example of the relationship between the reproduction light intensity and the reference light angle when the angle correction data is reproduced. When reproducing the angle correction data, for example, the reproduction light intensity is detected while changing the angle of the reference light minutely. At this time, when the reference light angle is plotted on the horizontal axis and the reproduced light intensity is plotted on the vertical axis, as shown in the figure, N peaks equal to the number of recording pages can be observed. The reference beam angles θ ₁ to θ _N suitable for reproducing the N pages of the angle correction data may be, for example, the reference beam angles at which the reproduction light intensity is the largest in each area that divides the reference beam angle range into N parts, or may be Let it be the reference light angle at which the reproduced light intensity exceeds a predetermined threshold.

Correction of the zero point and unit amount of the reference beam angle is performed, for example, as follows. Assuming that the reference light angle suitable for reproducing N pages of angle correction data is θ ₁ to θ _N , the theoretically predicted detection prediction angle is to The detected predicted angle is calculated based on information on angle correction data stored in a memory provided in the optical information recording medium or a cartridge containing the medium, in the memory of the device, or in the memory of a device for controlling the device. This detection prediction angle may be used as a reference light angle at the time of recording, and may be calculated by taking into account the effects of medium shrinkage due to curing and expansion and contraction of the medium due to temperature changes. In this case, the correction coefficient α of the unit amount of the reference light angle is represented by, for example, the following formula.

At the time of recording and reproduction, the value of the reference beam angle θ is multiplied by α. On the other hand, the zero-point correction value Δθ of the reference light angle is represented by, for example, the following equation.

The corrected value of the reference light angle θ is applied to αθ+Δθ by applying these α and Δθ. However, α and Δθ are not limited to the above formula, for example, instead of taking the average, you may use Such a formula.

In addition, it may be divided into predetermined angle areas, and correction of the zero point and unit amount of the reference beam angle may be performed. In this way, the correction can be performed in consideration of the influence of the case where the deviation of the angle of the reference light greatly differs depending on the angle area.

In addition, when it is not necessary to correct the unit amount of the reference beam angle, the correction coefficient α may be set to 1.

Fig. 8 is a flowchart showing an embodiment when a medium is loaded in the optical information recording and reproducing apparatus. When the optical information recording medium is loaded in the optical information recording and reproducing apparatus, it is first judged by 501 whether it is an unrecorded medium or not. The information recorded on the medium is managed by being recorded in, for example, the medium itself or in a control data area provided in a cartridge storing the medium, and is determined by referring to the control data area in 501 . In the case of an unrecorded medium, step 502 records the data for angle correction in the area for angle correction in the optical information recording medium. After that, in step 503, information is recorded and reproduced. If it is determined in 501 that it is not an unrecorded medium, angle correction of the reference beam is performed in 504 , and then information recording and reproduction in 503 are performed. However, when correcting the angle of the reference beam, information on the intensity of the reproduced light when the angle of the reference beam is slightly changed as shown in FIG. The side changes slightly within the scannable range, and at the same time irradiates the reference light to the medium, and the intensity of the reproduced signal light is detected by the photodetector, and the relationship between the angle of the reference light and the intensity of the reproduced light can be obtained from this.

9 is a flowchart showing an example of the operation of reference beam angle correction in the optical information recording and reproducing apparatus. When the angle correction of the reference light is performed, the position of the optical disk is aligned in the area for angle correction through 601 (so that the pickup is aligned with the area). After that, the angle correction data recorded in the optical information recording medium is reproduced in step 602 , and the angle correction amount is learned in step 603 based on the reproduced data. Finally, 604 is used to correct the zero point and unit amount of the reference light angle.

FIG. 1 is a schematic diagram showing the outline of the present invention. In the area for angle correction in the optical information recording medium 1 , the data for angle correction is recorded by the first device A to record on the optical information recording medium. Afterwards, when the same optical information recording medium is used in other devices, the angle correction data is first referred to, and the zero point and unit amount of the reference light angle are consistent with those of the first recording device A, and then recording and reproduction are performed.

Note that the angle correction data may be a white page in which the entire area of the page is composed of ON pixels, or may be a page generated by modulating data such as management information and detected predicted angles. An advantage of using a blank page is, for example, that since there is no arrangement error of ON pixels and OFF pixels, recording can be performed under equal conditions for all pixels in the page. An advantage of using pages generated by modulating data such as management information and detected and predicted angles is that, for example, since information is also recorded in the angle correction area, there is less waste in terms of recording density.

According to the above structure, in the first embodiment of the present invention, by referring to the angle correction data recorded in the optical information recording medium, the zero point and unit amount of the reference light angle can be corrected between devices, and compatibility between devices can be achieved. Highly accurate recording reproduction. In addition, in this embodiment, there is an advantage that it can be implemented while keeping the structure of the device substantially the same as that of a conventional optical information recording and reproducing device.

[Example 2]

2nd Example in this invention is demonstrated using FIG.10, FIG.11. In this embodiment, when referring to the angle correction data of the reference light, a so-called optical coherence technique is used in which light to which the angle correction data is added is incident from the signal light path and the reproduced reference light is detected. Wherein, descriptions of parts common to the above-mentioned embodiments are omitted.

Fig. 10 shows an example of a pickup in the optical information recording and reproducing apparatus. In this embodiment, in addition to the basic optical system structure of FIG. 3 , the reference light diffracted from the optical information recording medium 1 is reflected on the galvanometer mirror 231 , enters the lens 232 , and converges on the photodetector 233 .

When searching for a reference light angle suitable for reproducing the data for angle correction, a two-dimensional pattern of ON and OFF corresponding to the data for angle correction is displayed on the pixel of the spatial light modulator 212, and the light beam is irradiated to On the optical information recording medium 1, the diffracted light is thus reproduced.

11 is a schematic diagram showing an example of a relationship between a diffracted light angle and a detection position when searching for a reference light angle corresponding to angle correction data. For example, as shown in the figure, the lens 232 is arranged at a position whose distance from the hologram in the optical information recording medium 1 as the search object is the focal length f of the lens 232, and then is parallel to the lens 232 at the next position f. The photodetector 233 is arranged in a grounded manner. The center position of the photodetector 233 is located on the axis of the lens 232 . When the angle between the diffracted light and the axis is b, the position x of the bright spot on the photodetector is represented by, for example, Equation (3).

x=f sinb...(3)

In addition, the relationship between the angle a between the information recording medium 1 and the diffracted light and the above b, when the angle formed by the plane perpendicular to the optical axis of the lens 232 and the plane perpendicular to the rotation axis of the optical information recording medium 1 is c , such as expressed by formula (4).

a=b+c......(4)

Therefore, by detecting the position x of the bright spot with the photodetector 233, angle information of the reproduced diffracted light can be obtained, and a reference light angle suitable for reproduction can be calculated based on this information.

Here, as the photodetector 233, a photodetector capable of two-dimensionally detecting light information such as a CMOS image sensor may be used, or a photodetector capable of one-dimensionally detecting light information such as a line sensor may be used. The pixel size of the photodetector 233 may be a pixel size having an angular resolution necessary to optimally control the angle of the reference light, but if the bright spot can be calculated by using position information and brightness information of each pixel of the photodetector 233 to obtain the necessary angular resolution, a larger pixel size is also possible. In addition, if necessary, the focal length of the lens 232 may be increased to form a magnification system, thereby improving the resolution of angle information detection.

According to the above structure, in the second embodiment of the present invention, by referring to the angle correction data recorded in the optical information recording medium, the zero point and the unit amount of the reference light angle can be corrected between devices, and high compatibility can be achieved. record reproduction. In addition, in this embodiment, when referring to the data for angle correction, it is not necessary to scan the angle of the reference beam finely, so there is an advantage that high-speed correction is possible.

In addition, this invention is not limited to the said Example, Various modification examples are included. For example, the above-mentioned embodiments are described in detail to make the present invention easy to understand, and are not limited to having all the described features. In addition, it is possible to replace part of the features of a certain example with features of another example, or to add features of another example to the features of a certain example. In addition, other features can be added, deleted, or substituted for some of the features of the respective embodiments.

In addition, a part or all of the above-mentioned features, functions, processing units, processing units, etc. may be realized by hardware, for example, by designing an integrated circuit or the like. In addition, the above-mentioned features, functions, and the like can also be realized by software by interpreting and executing a program that realizes each function by a processor. Information such as programs, tables, and files that realize each function can be stored in recording devices such as memory, hard disk, and SSD (Solid State Drive), or recording media such as IC cards, SD cards, and DVDs.

In addition, the control lines and information lines indicate the necessary parts in the description, and do not necessarily indicate all the control lines and information lines on the product. In fact, it can also be considered that almost all structures are connected to each other.

Claims (12)

1. An optical information recording and reproducing device, which utilizes holography to record and/or reproduce information on an optical information recording medium, is characterized in that it includes: an angle detection section detecting first angle information on a reference light angle suitable for reproducing the angle correction data recorded in the optical information recording medium; and The angle correction unit adjusts the angle of the reference light at the time of recording or reproduction based on the first angle information detected by the angle detection unit and second angle information about the angle of the reference light at the time when the data for angle correction is recorded. make corrections, The angle correction unit corrects the zero point of the angle of the reference light and the magnitude of the unit amount before recording or reproducing information. 2. The optical information recording and reproducing apparatus according to claim 1, wherein: The angle detection unit detects the angle correction data while changing the angle of the reference light, and sets a reference light angle when the detected intensity of the reproduction light reaches a maximum value as a reference suitable for reproduction of the angle correction data. light angle. 3. The optical information recording and reproducing apparatus according to claim 1, wherein: The angle detection unit irradiates the light to which the angle correction data is added from the optical path of the signal light at the time of recording, detects the diffracted light with a photodetector, and calculates an appropriate angle based on position information of the diffracted light on the photodetector. Correct the reference beam angle for reproduction of the data. 4. The optical information recording and reproducing device according to claim 1, characterized in that: Presence or absence of information recording in the angle correction data area in the optical information recording medium, control data for recording information on the optical information recording medium in the optical information recording medium or in the box containing the optical information recording medium in the area. 5. The optical information recording and reproducing device according to claim 1, characterized in that: The angle correction data is recorded by the first optical information recording and reproducing device that records the optical information recording medium. 6. The optical information recording and reproducing apparatus according to claim 1, wherein: The angle correction data is stored in advance in the optical information recording medium at the time of shipment. 7. A method for recording and reproducing optical information, using holography to record and/or reproduce information on an optical information recording medium, characterized in that it includes: an angle detection step of detecting first angle information on a reference light angle suitable for reproducing the angle correction data recorded in said optical information recording medium; and an angle correcting step of correcting a reference beam angle during recording or reproduction based on the angle information detected by the angle detecting step and second angle information on a reference beam angle when the angle correction data is recorded, In the angle correction step, before recording or reproducing information, the zero point of the angle of the reference light and the magnitude of the unit quantity are corrected. 8. The optical information recording and reproducing method according to claim 7, characterized in that: In the angle detection step, the angle correction data is detected while changing the reference light angle, and the reference light angle when the detected reproduction light intensity is at a maximum value is set as a reference suitable for reproduction of the angle correction data. light angle. 9. The optical information recording and reproducing method according to claim 7, characterized in that: In the angle detection step, the light to which the angle correction data is added is irradiated from the optical path of the signal light at the time of recording, the diffracted light is detected by the photodetection step, and an appropriate The reference beam angle for reproduction of angle correction data. 10. The optical information recording and reproducing method according to claim 7, characterized in that: Presence or absence of information recording in the angle correction data area in the optical information recording medium, control data for recording information on the optical information recording medium in the optical information recording medium or in the box containing the optical information recording medium in the area. 11. The optical information recording and reproducing method according to claim 7, characterized in that: The angle correction data is recorded by the first optical information recording and reproducing device that records the optical information recording medium. 12. The optical information recording and reproducing method according to claim 7, characterized in that: The angle correction data is stored in advance in the optical information recording medium at the time of shipment.